As linebacker Bobby Wagner signs a four-year contract extension to remain in Seattle through 2019, take a look back at the best photos from his time with the Seahawks.

Assembling the Seahawks’ very formidable defensive line has been like wedging the pieces of a human puzzle into place.

Pete Carroll wants to play defense a certain way, and the team’s second-year coach needs certain types of players to do it. So he and general manager John Schneider rolled up their talent-finding sleeves and set out to do just that when they arrived in January of 2010.

Last year, little-used defensive tackle Red Bryant was moved to the five-technique end spot, where his overwhelming size (6-foot-4, 330 pounds), coupled with deceiving speed and agility, make him a combination that’s difficult to beat. Also, Chris Clemons was acquired in a trade with the Philadelphia Eagles to fill the hybrid “Leo” end position, where the 254-pounder has turned into a greased pig of a penetrator as a rush-rusher and surprisingly effective run-stopper.

This year, Brandon Mebane was moved from three-technique tackle to nose tackle, where his wide body (6-1, 311) and explosive quickness create even more problems for opposing blockers. Alan Branch was then signed in free agency to fill the spot where Mebane had started the past four seasons, and Branch’s complete package of length and bulk (6-6, 325) have been a perfect complement against the run and the pass.

They now comprise a foursome that has been the foundation of a Seahawks defense that ranks among the league’s best in average rushing yards allowed per game and carry entering tonight’s nationally televised game against the Philadelphia Eagles at CenturyLink Field.

“You don’t really have big-name guys on our defense,” Clemons said. “Everybody always says we’re so far out here that nobody else pays attention to us. We don’t think about that kind of stuff. We come to work. We do our job. That’s what we do.”

And no one has been doing it better than Clemons, who also has played with the Washington Redskins, Oakland Raiders and Eagles but never was allowed to be an every-down player. Before coming to the Seahawks last year, he had started three games in five seasons. Tonight, he’ll make his 28th consecutive start.

“When I got here, I told coach, ‘My thing is, I just want to play,’ ” Clemons said. “Things just changed once I got here. They gave me an opportunity to come out and play, and I just took advantage of it.”

Did he ever, and by playing at an extremely high level. Clemons led the Seahawks in sacks last season, with a career-high 11. This season, he’s on pace to top that. Clemons had a career-best three sacks in the Week 11 win over the Rams in St. Louis, as well as two forced fumbles, to earn NFC Defensive Player of the Week. The last Seahawks’ defender to be honored was cornerback Josh Wilson in 2008.

But if Clemons had a vote, he’d cast it for Bryant. And Mebane. And Branch. And even backups Raheem Brock, Anthony Hargrove and Clinton McDonald, who also have been productive in the rotation used by defensive coordinator Gus Bradley and D-line coach Todd Wash.

Clemons on Bryant, who missed the second half of last season with a knee injury: “I’m just proud of the big fella. He went through a lot last year with the knee surgery. But now he’s showing each and every week how much better he’s getting. To me, it’s almost like seeing your little brother get the opportunity.”

Clemons on Mebane, who has been nicknamed “Bang-Bang” but also goes by “Bane”: “ ‘Bane doesn’t get a lot of credit. But to me, ‘Bane’ is by far one of the best defensive tackles in the league. When you get a guy that explosive and that disruptive who can just disrupt the whole flow of offense, what more can you ask for from a defensive tackle? You never see ‘Bane’ get blown off the ball. You never see ‘Bane’ get thrown out of his gap. ‘Bane’ is always making plays in the backfield.”

Clemons on Branch, who started only three games the past four seasons with the Arizona Cardinals: “He brings a lot. He brings size. He brings height. He brings a skill set because of those long arms of his. On the pass rush, he moves the pocket. Once he saw how we roll, he immediately grabbed on and just rolled with us. He’s been playing great ball.”

Clemons on the group: “We just hold each other accountable, just knowing and understanding what everybody is thinking at the same time.”

That definitely is the tune these guys sing whenever asked about themselves: One for all, all for one, and that’s the only way to get the job done.

Wash, who joined the coaching staff this year after four seasons with the Tampa Bay Buccaneers and three times that in the college ranks, has been struck by just how tight his group is.

“I’ve been coaching for 19 years, and this is my fifth in the NFL, and I thought we’d had some good (meeting) rooms before,” he said. “Nothing against those, but it’s not even close as tight knit as these guys are in that room for us.”

Mebane and Bryant have talked about that camaraderie before, and Clemons can only echo their sentiments.

“The thing is, everybody is focused, everybody is in tune to what coach wants us to do,” he said. “The biggest thing this year is, a lot us nobody else wanted us. But everybody has a home here, everybody is happy to be here and be together.

“That’s one of the things with our group, we all just stick together throughout everything. That’s the reason we go out there and give it everything we have, because as I tell them all the time, ‘I’m not playing for myself. I’m playing for everybody on the D-line.’ That’s the way everybody approaches it every week.”

But his linemates also step out of this we-are-one mentality to make sure Clemons – or Clem, as they call him – gets his due. They might throw in the occasional barbs, but it’s all good – and good natured.

“Clem is a phenomenal end,” Bryant said. “Clem will make you raise your standard of play because you know what you’re going to get out of that guy. He plays the game the way it’s supposed to be played.

“And when you’re playing with a guy like that, you want to hold up your end.”

Bryant then continued by offering the bottom-line assessment of Clemons’ contributions, “Clem is underrated. But that’s what he fuels off of. But those of us in this locker room, we hold him in high regard and we know what he brings to the table. He’s non-stop, relentless, mean, tough.”

That’s when Mebane leaned in to add, “Ugly.”

After a robust round of belly laughs, Bryant said, “He’s all that. What else can you say about Clem? He’s the man.”

A man among other bigger men; not to mention a unit that is making a big difference for the defense and the entire team.

“It’s just such a special group,” Clemons said. “And I think this group can carry this team along way.”